1. Field of the Invention
The present invention relates to a pipe joint for removably coupling a socket and a plug by means of lock balls provided in the socket by actuating an operating sleeve.
2. Description of the Related Art
A great number of pipe joints comprising a socket having lock balls, which are pressed or released by an operating sleeve, and a plug having engaging grooves in/from which the lock balls are engaged/disengaged have been manufactured and used. A socket having an operating sleeve and lock balls has a more complicated structure than a plug. In particular, a socket including a valve body has a further complicated structure and influences the manufacturing cost of the pipe joint.
This type of conventional socket of a pipe joint generally includes a valve receiving portion fixed on the inner periphery of the socket, a valve body urged by a spring at the time of coupling to come into contact with a valve seat and to close a fluid passage, and a lock ball receiving portion for preventing lock balls from projecting out of the inner peripheral surface of the socket. These components are generally formed separately and not integrated (Jap. U.M. Appln. KOKAI No. 51-34023).
The assembly of the pipe joint having the above structure is time-consuming and troublesome, resulting in a main factor of an increase in the manufacturing cost.